Emergency 9-1-1 service has been designated in the U.S. as the emergency system for public use for emergency reporting to and/or requesting emergency assistance from public safety entities, typically for dispatch of emergency service providers (ESPs) (e.g., law enforcement, firefighters, emergency medical service (EMS)) to the scene of the emergency. An integral functional feature of existing 9-1-1 networks is that a call placed to 9-1-1 from anywhere within a calling region can be quickly directed to the appropriate ESP that can get to the site of the emergency the quickest, if necessary, in lieu of the need to directly dial the ten digit telephone number of the ESP. Current 9-1-1 emergency service capabilities range from traditional or basic 9-1-1 emergency service to enhanced or E911 emergency service.
Current 9-1-1 service has specific processing features that are designed to improve its functionality (e.g., ease of use, uniformity, etc.), and to reflect that time is of the essence in handling an emergency call. An enabling process for such features is the capability to determine, from call signal information (i.e., automatically), the geographic location of the calling party. The geographic source of the call has to be sufficiently precise so that the call can be immediately routed from anywhere within the calling region in which it is placed, to a predetermined public safety answering point (PSAP) in a given jurisdiction (e.g., municipality, county, etc.), where it is first “answered” by an operator or “call taker.” The call is then transferred or communicated from the PSAP to a predetermined ESP(s) for disposition based upon, for example, proximity to the site of the emergency.
Current processing features of the 9-1-1 infrastructure have developed around the use of traditional wireline technology that uses circuit-switched telephony (e.g., public switched telephone networks (PSTNs)), which is characterized by nominal subscribers using landlines at fixed geographic locations. Such features have evolved to provide access to the existing 9-1-1 networks for 9-1-1 calls originating from wireless telecommunications technology. For wireline placed 9-1-1 calls, the geographic location of the caller for purposes of PSAP routing can be determined automatically from the exchange portion of the calling party's telephone number (i.e., the first three digits), or from the calling party's entire telephone number (i.e., from caller identification (“ID”)). For cellular placed 9-1-1 calls, the geographic location of the caller for purposes of PSAP routing can be determined automatically from location information regarding the operative cell tower, or from global positioning system (GPS) data.
Internet telephony, such as voice over IP (VoIP) phone service, is reportedly poised to become the predominant technology used in the telecommunications industry. Thus, emergency calls will increasingly be placed from VoIP devices. Current VoIP offerings, however, fail to adequately provide suitable 9-1-1 network service, in part, due to the technological challenges in automatically determining the source of the 9-1-1 call, i.e., the specific geographical location of the VoIP device.
A VoIP placed call can originate from a VoIP user device and enter the Internet as a signal that is geographically nondescriptive. The call can be routed through the Internet to a PSTN that is geographically remote from the VoIP user device. Additionally, because VoIP user devices can be readily relocated and used at any available suitable network connection, the VoIP subscriber's fixed physical address that can be associated with the subscriber's phone number is not always going to be the originating location of the call. Thus, the “nomadic” use of VoIP telephony can operate to obscure the source of the VoIP placed call.
Proposed methods to provide 9-1-1 network access to VoIP users include diverting the VoIP-placed 9-1-1 call to the PSTN based on the VoIP subscriber's fixed address location. However, such processing can only be accomplished when the VoIP device is used at the subscriber's address location, and the VoIP subscriber has successfully registered the correct address information with the VoIP service provider, etc. Otherwise, the 9-1-1 call is simply dropped, or the 9-1-1 service disabled when used at an alternative or remote location. Thus, proposed methods to interface IP-enabled telecommunications to conventional 9-1-1 service are largely unavailable to VoIP device users. Accordingly, local service access VoIP systems do not process 9-1-1 calls in the manner that landline and cellular phones do, and thus such calls are not handled with the exceptional level of care and priority afforded to wired and cellular telephone calls to 9-1-1.
The effectiveness of the 9-1-1 emergency reporting system relates to public expectations regarding its convenience and uniformity. Thus, it is desirable to standardize 9-1-1 call processing, from the perspective of the caller, regardless of the telecommunications technology used to place the call to 9-1-1. Moreover, it is likely that government regulations and/or industry-adopted standards will soon require VoIP-enabled calls to 9-1-1 to have the “look and feel” of conventional 9-1-1 calls.